Tab Information Lost with Bad Addresses

 

Summary

Mozilla FireFox implements a tabbed browsing system, where a user can open multiple pages into a single browser window. If an address being loaded into the tabs is invalid, FireFox displays an error message, but then erases the address from the address bar.

Application Description

Mozilla's FireFox is an Internet browser available for Linux, MacOS, and Windows. At the time of writing this presentation, FireFox was still pre-1.0 (meaning that it was still a preview release for testing purposes).

Test Design

This example demonstrates the use of Scenario testing. In scenario testing, we create a hypothetical situation the program could be run through, and then we run through it ourselves based on that situation. This helps us to evaluate the program's real-world adaptibility, as well as help us to test many functions that are not frequently used or tested (or simply aren't tested thoroughly enough).

In this presentation, let's imagine we work as a search engine site checker. Each day we get a list of hundreds of sites, and we have to browse to them and classify those sites based on the content. We use FireFox's tab feature to open all the sites, reading over one page while the other pages load.

We expect that when we move between the tabs, each tab will maintain the information that we have entered into it.

We are using Scenario testing to tackle FireFox's tabbed browsing feature for one reason: tabbed browsing is so expansive and so integrated into the browser that it would be easy to miss testing many of its features if we did not utilize a testing technique that attempted to come at it from all angles.

Performing the Test

  1. Open Mozilla FireFox:

  2. Open a new tab by pressing Ctrl-T or by clicking on File->New Tab on the top horiztonal menu:


  3. In the address bar, type in http://www.rlkasjdkajsdkjasdf;kjsadjk;ld.com-net.edu/org or (any other address you know to be false).
  4. Switch back to the first tab, as if we had some work to do in it.
  5. FireFox will try to load the false address in the second tab, and once it establishes it cannot, we recieve the following error:

  6. Press 'OK' on the warning box, and then switch back to the second tab:

Results/Relevance

When we switched back to the second tab, the address that we had typed in was lost. Unless we had closely read the error message, we would not be sure which site we had just attempted to visit. And to further enhance our scenario, we had said that we would be checking hundreds of sites, so what would happen if we had fifty websites open, and 1 (or many) of them had this error. How do we know which site we have lost? Unless we have kept all of the sites in some order, which would of course have been nice, we would have to search through our list to find the one that was not up there and try it again to verify.

Similar Tests/Additional Notes

More information on the bug in this presentation can be found on the Mozilla bugzilla site.

Configuration Notes

Testing Mozilla's FireFox v0.9 on:

Created 29 June 2004 for the CSTER

All images and written material ©Copyright Sam Oswald 2004

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